Add escaped quote tests for tagged literal handlers

Tests the full pipeline for escaped quotes in #re and #b: tokenizer
preserves backslash-quote in raw content, handler interprets it as a
literal quote in the output. Also fixes scanRegexContents javadoc.

Author: sugmanue

smithy-model/src/test/java/software/amazon/smithy/model/loader/TaggedStringLiteralTest.java

@@ -29,6 +29,7 @@ public static Stream<Arguments> reTagTests() {
                 Arguments.of("\\w+\\s\\d", "\\w+\\s\\d"),
                 Arguments.of("\\\\", "\\"),
                 Arguments.of("\\\"", "\""),
+                Arguments.of("a\\\"b", "a\"b"),
                 Arguments.of("hello", "hello"),
                 Arguments.of("", ""),
                 Arguments.of("[a-z]+\\.(\\d{1,3}\\.){3}\\d{1,3}", "[a-z]+\\.(\\d{1,3}\\.){3}\\d{1,3}"));
@@ -78,6 +79,8 @@ public static Stream<Arguments> bTagTests() {
                 Arguments.of("\\377", base64((byte) 0xFF)), // max single byte
                 Arguments.of("\\7", base64((byte) 7)), // single octal digit
                 Arguments.of("\\77", base64((byte) 63)), // two octal digits
+                // Escaped quote
+                Arguments.of("a\\\"b", base64((byte) 'a', (byte) '"', (byte) 'b')),
                 Arguments.of("", base64()));
     }
 

smithy-model/src/test/resources/software/amazon/smithy/model/loader/valid/2.1/tagged-literals.json

@@ -13,6 +13,12 @@
                 "smithy.api#pattern": "\\w+"
             }
         },
+        "smithy.example#QuoteInRegex": {
+            "type": "string",
+            "traits": {
+                "smithy.api#pattern": "a\"b"
+            }
+        },
         "smithy.example#TaggedLiteralsExample": {
             "type": "structure",
             "members": {
@@ -28,6 +34,12 @@
                         "smithy.api#default": "LlBORw0KGgo="
                     }
                 },
+                "quoted": {
+                    "target": "smithy.api#Blob",
+                    "traits": {
+                        "smithy.api#default": "YSJi"
+                    }
+                },
                 "header": {
                     "target": "smithy.api#Blob",
                     "traits": {

smithy-model/src/test/resources/software/amazon/smithy/model/loader/valid/2.1/tagged-literals.smithy

@@ -8,13 +8,19 @@ string Ssn
 @pattern(#re "\w+")
 string Word
 
+@pattern(#re "a\"b")
+string QuoteInRegex
+
 structure TaggedLiteralsExample {
     @default(#timestamp "2024-01-01T00:00:00Z")
     startDate: Timestamp
 
     @default(#b ".PNG\x0D\x0A\x1A\x0A")
     avatar: Blob
 
+    @default(#b "a\"b")
+    quoted: Blob
+
     @default(#hex "89504e47")
     header: Blob
 }